This invention relates to pens, more particularly to a retractable pen.
There are many instances where it would be desirable to be able to provide a retractable pen with a mechanism to allow a user to magnetically attach a pen to a cap in a single-hand operation, and to simultaneously retract the writing tip.
A number of patents disclose retractable pens.
U.S. Pat. No. 6,394,677 discloses xe2x80x9cHanging pen and cord thereofxe2x80x9d. This prior art pen has a pen cap, and a penholder. The pen cap has a blocking cover with a loop cord for carrying and an opening at the other end. The penholder provides a center stick therein with a writing head of the center stick extending outwardly from a conical part at an end of the penholder. A magnetic ring is fixed in the pen cap. The conical part is made of magnet inducing material. The pen cap engages the penholder by way of the magnetic ring attracting the conical part when the conical part is inserted into the pen cap from the open end.
These prior art arrangements do not provide a retractable pen with a mechanism to allow a user to magnetically attach a pen to a cap in a single-hand operation. In addition, prior art retractable pens do not simultaneously retract the writing tip when the pen is attached to the cap. Moreover, prior art retractable pens do not provide a cushion effect to the writing tip.
It is a primary object of the invention to provide a retractable pen in which a pen magnetically attaches to a cap in a single-hand operation by the user.
It is another object of the invention to provide a retractable pen which simultaneously retract the writing tip when the pen is attached to the cap.
It is another object of the invention to provide a retractable pen in which the pen stays upside up and downside down when attached to the cap.
It is another object of the invention to provide a retractable pen which has a cushion effect.
It is another object of the invention to provide a retractable pen which has a loop-shaped cord to be worn by the user around his/her neck.
A retractable pen comprises a pen and a cap. The pen comprises a hollow case, an ink cartridge, a mechanical spring and a mobile magnetic element. The cap comprises a cap body and a stationary permanent magnet. The pen is capable of attaching to the cap by the magnetic attraction force in a single-hand operation when a user places the mobile magnetic element of the pen in proximity to the stationary permanent magnet of the cap. The writing tip of the ink cartridge of the pen retracts into the hollow case of the pen when an upward magnetic attraction force is greater than a downward mechanical expansion force.